The Office was, until he left, Steve Carell's show. And he maintains an A-list career. Mindy Kaling, who writes for the show and plays Kelly, may not have the same star power—but on Twitter, where she's far more active than Carell, she's rewarded in kind: She has triple the followers (1.8 million versus 650,000 in July) and actively engages others (76% of her tweets include an @mention, versus 17% for Carell). Not that it's a competition. But as networks weigh actors' social potential, it's no wonder she's been given her own Fox vehicle, The Mindy Project.

Mindy Says...

A slice of social media wisdom...in 140 characters.

"Twitter is so short, it's safe. I don't want my bosses to be like, "Hey, your script is due and we saw you wrote four blog pages."

"People take things at face value on social media. Earnestness is the assumption."

"I don't know—maybe two-thirds of my followers are spambots."

"Twitter is basically a more playful way to text a friend."

"I don't actually know if any people care about a specific tweet of mine, but I have fun."

The network hasn't assigned her social marching orders yet, but she heaps praise on Joe Earley, its head of marketing and communications. "He was the one who made New Girl available for download a week before it aired," she says. "It was extremely smart. He knows the power of social media and how it can help a show."

Kaling didn't join Twitter to hawk her stuff; she was just coming up with jokes and too lazy to grab a notebook. And she's since decided that the best promotion is no promotion. "People don't want to listen to a celebrity tweeting about their charities and shows," she says. "That's why comedy writers do well—we put out little funny ideas." She took us through a day (Thursday, June 21) of @MindyKaling.

7:35 A.M.

Seeking a Movie For The End Of The World. So excited to see @SteveCarell in brilliant @LoreneScafaria's new movie.
Kaling was lying on the floor in her gym clothes, procrastinating. Then she remembered her friends' movie.
"I never tweet about something if I really don't like it," she says. "I'd rather have a friend annoyed at me than do that, because it just feels like a lie."

7:58 a.m.

It's a jog-to-Drake's-Best-I-Ever-Had 11 times in a row kinda morning I guess
After going on a run, she tweeted a nod to fans who read her book, Is Everyone Hanging Out Without Me? (And Other Concerns). It had a bit about exercising with one song on repeat. "When you listen to one song 12 times in a row you seem like you're getting pumped up to, like, murder the president or something," she says.

Follow Fast Company's roadmap to social media: surefire rules, data, and expert wisdom guaranteed to show why this market is completely unpredictable.

9:04 A.M.

Did you hear about the awesome new Aaron Sorkin/Rihanna collaboration? it's called "Walk That Talk" and it is amazing you guys
Twitter followers love recognizing celebs' interests: It's like a formula to what makes someone tick. Kaling says this joke hit two big, recurring topics for her: TV writing and urban music. "I was almost trembling with how excited I was for this incredibly stupid pun," she says. And bonus: Brooklyn Decker retweeted it. "That made me feel cool," she says.

7:18 P.M.

@KenTremendous@sepinwall and Mike's impression of the kid in Amish in the City made us retrofit a character for him to play on the show!
Office producer Mike Schur and TV critic Alan Sepinwall had been tweeting at each other, and brought in Kaling. "Then I got into a little sentimental journey," she says. (This is from that exchange.) As celebrities know, fans aren't the only ones who appreciate access.

9:16 P.M.

Hey @JeremyBronson sorry I screamed so much on the Transformers ride.
The writers' computers at The Mindy Project went down for 45 minutes, so the team went next door to Universal Studios. After, Kaling sent this to a fellow writer. She prefers Twitter to just about any medium, even for personal notes. "When Jimmy Fallon had released his head monologue writer [Bronson] to come and work on this show, I thanked Jimmy on Twitter. A note sent personally is very classy, but to say it in front of a lot of people, I think, has an even nicer meaning because I'm acknowledging it publicly."

9:17 P.M.

"@sethmeyers21: @mindykaling You've learned Hollywood's most important lesson - Don't let @ikebarinholtz order pizza." Matt and I fired him
Every TV show has characters, and Kaling's Twitter feed needs characters as well. Her writers—especially Ike Barinholtz (best known as Ivan Dochenko from Eastbound and Down)—fill that role, because she's mostly tweeting from the writer's room. In this case, she says, "Fast food is hugely important in the life of a comedy writer. All we do is order in, and what we're going to eat is hotly debated."

9:31 P.M.

Don't worry @davidstassen your job is safe. Wanna be writing partners with Josh Meyers?
It's late on Thursday—pretty much the cliff for Twitter, which a Bitly study finds is most trafficked from
9 a.m. to 3 p.m. on Monday through Thursday, and sinks especially hard after 8 p.m. So Kaling is free to get really insider-ish here, joking with one of her writers and Seth Meyers's brother (and Ike Barinholtz's onetime comedy partner—really insider-ish!). "It's a really good medium for teasing people," she says, "and comedy writers love to tease people."

TV's Social Disparity

Fox is the dominant network on social media, but its new star, Mindy Kaling, still must strike out on her own.

American Idol's 2012 season finale drew 20.7 million people, its worst ratings ever. But it caused 696,000 to comment in social media, making it not only the hottest social finale of last season but the highest-commented TV episode of all time. (In second place, Pretty Little Liars drew 469,000 commenters.) And yet even during Fox shows—the network that receives the most social media commentary—the actual stars are rarely tweeted about.

TOTAL FACEBOOK AND TWITTER COMMENTS ABOUT SHOWS ON THE TOP 5 TV NETWORKS LAST SEASON

New Girl
Total comments: 506,591
% about Zooey Deschanel: 12

The X Factor
Total comments: 3,824,583
% about Simon Cowell: 7

Bones
Total comments: 181,892
% about Emily Deschanel: 3

Family Guy
Total comments: 338,468
% about Seth MacFarlane: 1

American Idol
Total comments: 6,124,117
% about Ryan Seacrest: 1

The Office
Total comments: 106,473
% about Mindy Kaling: .03

A version of this article appeared in the September 2012 issue of Fast Company
magazine.

Never miss a story.

Sign up for the Fast Company newsletter and get the best stories delivered to your inbox daily.